CN104423190B - Developing toner for electrostatic latent images, the manufacturing method of the toner and fixation method - Google Patents

Abstract

A kind of developing toner for electrostatic latent images of present invention offer, its manufacturing method and fixation method.The developing toner for electrostatic latent images of the present invention contains toner-particle.Toner-particle includes：Toner cores containing binding resin, shell, the acicular inorganic particles for coating toner cores surface.Shell contains thermosetting resin, and includes inorganic particles in inside.The length-width ratio of inorganic particles is 1.25 or more and 2.5 hereinafter, average major axis diameter and average short axis diameter are 300nm or less.

Description

Developing toner for electrostatic latent images, the manufacturing method of the toner and fixation method

Technical field

The present invention relates to a kind of developing toner for electrostatic latent images, developing toner for electrostatic latent images manufacturing method and make With the fixation method of developing toner for electrostatic latent images.

Background technology

In technical field involved by duplicator etc image forming apparatus, by using fixing roller etc. heating and Pressurization makes developing toner for electrostatic latent images fixing in recording medium (for example, paper).Toner components in toner due to It heats and pressurizes and melt or soften, to be fixed in recording medium.About such fixing, it is expected that energy saving when realizing fixing Change and the miniaturization of fixing device.Therefore, it is desirable to while obtaining a kind of heating and pressurization inhibiting fixing roller as possible, to record The toner that medium can be fixed well.

The toner for currently studying the toner-particle coated with Lauxite containing surface is used as above-mentioned be used for Form the toner of image.

Also, currently study following toner：Inorganic particles are added to by outside on the surface of its toner cores, and And the surface of the toner cores is coated with silane compound.

Invention content

However, the toner that surface is coated with Lauxite, needs high temperature due to the hardness of Lauxite in fixing.Its As a result, for example cost is caused to increase.Moreover, because charging property cannot appropriately be maintained, so for a long time in use, will produce aobvious Shadow ghost image or image deterioration.Wherein, development ghost image refers to following image deflects：When image is formed, since toner is excessive It charges and the part there is no electrostatic latent image is made also to develop, it is uneven to generate on the image.In addition, the surface of toner cores With the toner that silane compound coats, fixation performance and keeping quality are poor.That is, for existing toner, It is difficult to realize excellent fixation performance and maintains appropriate charging property.

The present invention in view of the above-mentioned prior art the problem of and make, its purpose is to provide a kind of electrostatic latent image is aobvious Shadow toner, even if also can when using this developing toner for electrostatic latent images with high rigidity thermosetting resin clad surface It is enough to realize and be fixed with substantially low fixing temperature and fixing load (fixing pressure), and appropriate electrification can be maintained for a long time Property.Also, the present invention also aims to provide the manufacturing method of above-mentioned developing toner for electrostatic latent images and using above-mentioned Developing toner for electrostatic latent images fixation method.

The gist of the invention is as follows.

The developing toner for electrostatic latent images of the present invention contains toner-particle.Toner-particle contains：It is set containing bonding Shell, the acicular inorganic particles on the surface of the toner cores of fat, the above-mentioned toner cores of cladding.Above-mentioned shell contains thermosetting property tree Fat, and include above-mentioned inorganic particles in inside.The length-width ratio of above-mentioned inorganic particles is 1.25 or more and 2.5 hereinafter, average major axis Diameter and average short axis diameter are 300nm or less.

The manufacturing method of developing toner for electrostatic latent images of the present invention includes：Prepare the toner cores for including binding resin Preparatory process and by shell be formed as coat toner cores surface formation process.Above-mentioned shell contains thermosetting resin, And include acicular inorganic particles in inside.The length-width ratio of above-mentioned inorganic particles is 1.25 or more and 2.5 hereinafter, average major axis diameter And average short axis diameter is 300nm or less.

In addition, making the developing toner for electrostatic latent images of the present invention be fixed on the fixation method of recording medium to include：It will be upper State the toner supply process, above-mentioned quiet to being supplied with that developing toner for electrostatic latent images is supplied to the surface of aforementioned recording medium The aforementioned recording medium of electric image development toner assigns 5N/cm²Above and 10N/cm²The load of load below assigns work Sequence.

In accordance with the invention it is possible to a kind of developing toner for electrostatic latent images is provided, this developing toner for electrostatic latent images Although, can be with sufficiently low fixing temperature and fixing load with the shell clad surface containing high rigidity thermosetting resin (fixing pressure) realizes fixing, and properly can maintain charging property for a long time.

Description of the drawings

Fig. 1 is the figure for indicating to constitute the toner-particle of the developing toner for electrostatic latent images of present embodiment.

Fig. 2 is the figure of the method for illustrating to measure softening point using high formula flow tester.

Fig. 3 be the another program for indicating present embodiment developing toner for electrostatic latent images in include toner-particle Figure.

Fig. 4 is the synoptic diagram of the fuser of the fixation method for present embodiment.

Fig. 5 is scanning electron microscope (SEM) picture of the developing toner for electrostatic latent images obtained by embodiment 1.

After Fig. 6 is included in the fixing of the toner-particle in the developing toner for electrostatic latent images obtained by embodiment 1 Surface SEM pictures.

Specific implementation mode

Hereinafter, detailed description of embodiments of the present invention.The present invention is not limited by the following embodiments and the accompanying drawings, In the range of the object of the invention, the present invention can be suitably changed to implement.In addition, for illustrating to repeat place, exist Appropriate the case where omitting the description, but therefore do not limit the objective of invention.

The developing toner for electrostatic latent images (hereinafter, being only known as toner sometimes) of present embodiment contains toner Grain.Toner-particle contains：The shell on the surface of the toner cores containing binding resin, the above-mentioned toner cores of cladding and needle-shaped Inorganic particles.Shell contains thermosetting resin, and includes above-mentioned inorganic particles in inside.The length-width ratio of acicular inorganic particles For 1.25 or more and 2.5 hereinafter, average major axis diameter and average short axis diameter are 300nm or less.In the present embodiment, toner Core shows anionic property (negatively charged), and shell shows cationic (positively charged).

Referring to Fig.1, the developing toner for electrostatic latent images of present embodiment is illustrated.

Developing toner for electrostatic latent images contains toner-particle 1.As shown in Figure 1, toner-particle 1 contains toner cores 2, shell 3 and inorganic particles 4.Also, the shell 3 containing thermosetting resin is formed as：Coat the surface of toner cores 2.It is inorganic The shape of particle 4 is needle-shaped.

By formed the shell 3 containing high rigidity thermosetting resin, make toner-particle 1 have excellent resistance to blocking, Transporting and keeping quality etc..When the developing toner for electrostatic latent images of present embodiment is supplied to the recording medium of paper, and And heat and load are endowed, then shell 3 is destroyed.Then, the toner cores 2 by exposing due to shell 3 is destroyed melt Or softening, to which fixing is in recording medium.

In toner-particle 1, since inorganic particles 4 become the starting point destroyed, although to contain high rigidity thermosetting 3 clad surface of shell of property resin, but shell 3 is also more easily damaged.As a result, fixing can fully be reduced in recording medium When temperature and load, while toner cores 2 being made to be fixed well in recording medium.Further, since inorganic particles 4 are in needle-shaped, So compared with spherical inorganic particles, haveing excellent performance for excessive charged particles is released, to the toner energy of present embodiment It is enough to maintain appropriate charging property for a long time.

Hereinafter, being illustrated to toner cores 2.

Toner cores 2 contain the binding resin as neccessary composition.Binding resin has anionic property.Binding resin is for example It is used as functional group with ester group, hydroxyl, carboxyl, amino, ether, acid group or methyl.In binding resin, preferably have in molecule There is the resin of the functional group of hydroxyl, carboxyl or amino etc, there is the resin of hydroxyl and/or carboxyl in more preferable molecule.Reason It is the unit (for example, melamine methylol) of this functional group and the monomer from the thermosetting resin included in shell 3 It reacts and is chemically combined.As a result, in toner-particle 1, shell 3 is securely joined with toner cores 2.

In the case where binding resin has carboxyl, in order to have sufficient anionic property, the preferably acid of the binding resin Value is 3mgKOH/g or more and 50mgKOH/g hereinafter, more preferably 10mgKOH/g or more and 40mgKOH/g or less.

In the case where binding resin has hydroxyl, in order to have sufficient anionic property, the preferably hydroxyl of the binding resin Value is 10mgKOH/g or more and 70mgKOH/g hereinafter, more preferably 15mgKOH/g or more and 50mgKOH/g or less.

As the concrete example of binding resin, it can be cited for example that thermoplastic resin (styrene resin, acrylic compounds tree Fat, styrene acrylic, polythylene resin, polypropylene-based resin, vinyl chloride resin, polyester resin, polyamide Resinoid, polyurethanes resin, polyvinyl alcohol resin, vinyl ethers resinoid, N- vinyl group resins or benzene second Alkene-butadiene type resin).In order to improve the dispersibility of the colorant in toner, the charging property of toner and to recording medium Fixation performance, optimization styrene acrylic resin and/or polyester resin are used as binding resin.

Styrene acrylic is the copolymer of styrene monomer and acrylic monomer.As phenylethylene list The concrete example of body, it can be cited for example that：Styrene, α-methylstyrene, 4-Vinyl phenol, hydroxy styrenes, toluene second Alkene, α-chlorostyrene, ortho-chlorostyrene, m-chlorostyrene, p-chlorostyrene or p -ethyl-styrene.

As the concrete example of acrylic monomer, can enumerate：(methyl) acrylic acid；(methyl) alkyl acrylate ((first Base) methyl acrylate, (methyl) ethyl acrylate, (methyl) n-propyl, (methyl) isopropyl acrylate, (methyl) third Olefin(e) acid N-butyl, (methyl) isobutyl acrylate, (methyl) 2-EHA；(methyl) acrylic acid hydroxy alkyl ester ((first Base) acrylic acid 2- ethoxys, (methyl) acrylic acid 3- hydroxypropyls, (methyl) acrylic acid 2- hydroxypropyls or (methyl) acrylic acid 4- hydroxyls Propyl).In addition, (methyl) acrylic acid means acrylic acid and methacrylic acid, (methyl) acrylate means acrylate And methacrylate.

When preparing styrene acrylic, by using monomer (4-Vinyl phenol, hydroxyl with hydroxyl Styrene or (methyl) acrylic acid hydroxy alkyl ester), hydroxyl can be introduced styrene acrylic.By suitably adjusting The dosage of monomer with hydroxyl can adjust the hydroxyl value of styrene acrylic.

When preparing styrene acrylic, by using (methyl) acrylic acid as monomer, carboxyl can be drawn Enter styrene acrylic.By suitably adjusting the dosage of (methyl) acrylic acid, styrene-acrylonitrile copolymer acids can be adjusted The acid value of resin.

Polyester resin can be by the polycondensation of carboxylic acid composition more than alcohol component and binary or ternary more than binary or ternary Or copolycondensation and obtain.

As the alcohol component of binary, it can be cited for example that：Glycols (ethylene glycol, diethylene glycol (DEG), triethylene glycol, 1,2-PD, 1,3-PD, 1,4-butanediol, neopentyl glycol, Isosorbide-5-Nitrae-butylene glycol, 1,5-PD, 1,6- hexylene glycols, Isosorbide-5-Nitrae-hexamethylene Dimethanol, dipropylene glycol (dipropanediol), polyethylene glycol, polypropylene glycol (poly-propanediol) or poly- tetramethylene Glycol)；Bisphenols (bisphenol-A, hydrogenated bisphenol A, polyoxyethylated bisphenol-A or polyoxypropylene bisphenol-A).More than ternary Alcohol component, it can be cited for example that：D-sorbite, 1,2,3,6- own tetrols, Isosorbide-5-Nitrae-sorbitan, pentaerythrite, two seasons penta Tetrol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5- penta triols, glycerine, two glycerine, 2- methyl glycerine, 2- methyl-1s, 2,4- butantriols, trimethylolethane, trimethylolpropane or 1,3,5- trihydroxytoluenes.

As the carboxylic acid composition of binary, it can be cited for example that：Maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconate, Phthalic acid, M-phthalic acid, terephthalic acid (TPA), cyclohexane cyclohexanedimethanodibasic, succinic acid, adipic acid, decanedioic acid, azelaic acid, third Diacid or alkyl succinic acid or alkenyl succinic acid are (for example, normal-butyl succinic acid, n-butene base succinic acid, isobutyl group amber Acid, isobutenyl succinic acid, n-octyl succinic acid, positive ocentyl succinic, dodecyl succinic acid, positive dodecenyl succinate Acid, Permethyl 99A base succinic acid or different dodecenyl-succinic acid).As carboxylic acid more than ternary, it can be cited for example that：1,2,4- Benzenetricarboxylic acid (trimellitic acid), 1,2,5- benzenetricarboxylic acids, 2,5,7- naphthalenetricarboxylic acids, 1,2,4- naphthalenetricarboxylic acids, 1,2,4- butane three Formic acid, 1,2,5- hexane tricarboxylic acids, 1,3- dicarboxyl -2- methyl -2- methylene carboxyls propane, 1,2,4- hexamethylene tricarboxylic acids, Four (methylene carboxyl) methane, 1,2,7,8- octane tetracarboxylic acids, pyromellitic acid or Empol trimer acids.The above carboxylic acid composition also may be used It is used using the derivative (acyl halide, acid anhydrides or lower alkyl esters) as ester formative.Here, " low alkyl group " refers to carbon The alkyl that atomicity is 1 to 6.

The acid value of polyester resin or the adjustment of hydroxyl value, can be when manufacturing polyester resin by suitably changing binary or ternary The dosage of above alcohol component and the dosage of carboxylic acid composition more than binary or ternary carry out.In addition, when increasing polyester resin Molecular weight when, the acid value or hydroxyl value of polyester resin have the tendency that reduction.

In the case where binding resin is polyester resin, in order to improve the intensity of toner cores 2 and determining for toner-particle 1 The number-average molecular weight Mn of shadow, preferred polyester resin is 1200 or more and 2000 or less.Due to reason same as described above, polyester Molecular weight distribution (value (the weight average molecular weight Mw/ number-average molecular weights of the ratio of number-average molecular weight Mn and weight average molecular weight Mw of resin Mn it is preferably)) 9 or more and 20 or less.

In the case where binding resin is styrene acrylic, in order to improve intensity and the toning of toner cores 2 The number-average molecular weight Mn of the fixation performance of agent particle 1, optimization styrene acrylic resin is 2000 or more and 3000 or less.Due to The molecular weight distribution (weight average molecular weight Mw/ number-average molecular weight Mn) of reason same as described above, styrene acrylic is excellent It is selected as 10 or more and 20 or less.In addition, the number-average molecular weight Mn and weight average molecular weight Mw of binding resin can use gel infiltration Chromatography measures.

In order to improve low-temperature fixability, the preferably glass transition temperature Tg of binding resin is the heat included in shell 3 Below the solidification start temperature of thermosetting resin.By making the glass transition temperature Tg of binding resin within the above range, in height Sufficient low-temperature fixability can be also realized when speed fixing.In particular, the glass transition temperature Tg of binding resin is preferably 20 DEG C or more, more preferably 30 DEG C or more and 55 DEG C hereinafter, further preferably 30 DEG C or more and 50 DEG C or less.In binding resin In the case that glass transition temperature Tg is 20 DEG C or more, toner cores 2 can be inhibited to be agglomerated when shell 3 is formed.It is general next It says, the solidification start temperature of thermosetting resin is 55 DEG C or so.

The glass transition temperature Tg of binding resin can use differential scanning calorimeter (DSC) by the ratio of binding resin The change point of heat is found out.More specifically, using differential scanning calorimeter (for example, what Japanese Seiko instrument Co., Ltd. manufactured " DSC-6200 ") it is used as measuring device, by measuring the endothermic curve of binding resin, the vitrifying that can find out binding resin turns Temperature Tg.As the other methods for the glass transition temperature Tg for finding out binding resin, following method can be enumerated：10mg's Sample (binding resin) is measured to be put into aluminium dish, using empty aluminium dish as reference, 25 DEG C of measuring temperature range or more and~ 200 DEG C or less, under conditions of 10 DEG C/min of heating rate, obtain the endothermic curve of binding resin, and according to the endothermic curve come Find out the glass transition temperature Tg of binding resin.

The softening point Tm of binding resin is preferably 100 DEG C hereinafter, more preferably 95 DEG C or less.By making softening point Tm be 100 DEG C when high speed is fixed hereinafter, can also realize sufficient low-temperature fixability.When adjusting the softening point Tm of binding resin, For example, as long as a variety of binding resins with different softening point Tm of combination carry out use.

When measuring the softening point Tm of binding resin, high formula flow tester can be used (for example, Shimano Inc " CFT-500D " manufactured by making).Specifically, will measure sample (binding resin) is placed in high formula flow tester, (die capillaries diameter 1mm, plunger load 20kg/cm under rated condition², 6 DEG C/minute of heating rate), make 1cm³Sample melted stream Go out, obtains S types curve (that is, S types curve about temperature (DEG C)/stroke (mm)), and binding resin is read according to the S type curves Softening point Tm.

With reference to Fig. 2, the read method of the softening point Tm of binding resin is illustrated.In fig. 2, make the maximum value of stroke For S₁, make to compare S₁Temperature by low temperature side baseline stroke value be S₂.The value of stroke in S type curves is (S₁+S₂When)/2, Using its temperature as the softening point Tm for measuring sample (binding resin).

With continued reference to Fig. 1, toner-particle 1 is illustrated.

Toner cores 2 can coordinate the color of developing toner for electrostatic latent images and contain as the well-known of colorant Pigments or dyes.As black color toner, carbon black can be enumerated.In addition, as black colorant, could be used that by following The colorant of yellow colorants, magenta coloring agent and cyan colorant etc reconcile into the colorant of black.

It, can be with as the colorant included in toner cores 2 when developing toner for electrostatic latent images is color toner It enumerates for example：Yellow colorants, magenta coloring agent or cyan colorant etc..

As yellow colorants, can enumerate：It is condensed azo-compound, isoindolinone compounds, anthraquinone compounds, idol Nitrogen metal complex, methylidyne compound or fragrant amide compound.Specifically, it can enumerate：C.I. pigment yellow (3,12,13, 14、15、17、62、74、83、93、94、95、97、109、110、111、120、127、128、129、147、151、154、155、 168,174,175,176,180,181,191 or 194), naphthol yellow S, Lufthansa Huang G or C.I. vat yellow.

As magenta coloring agent, can enumerate：It is condensed azo-compound, pyrrolo-pyrrole-dione compound, anthraquinone Close object, quinacridone compound, basic dye lake compound, naphthol compound, benzimidazolone compound, thioindigo compound Or compound.Specifically, it can enumerate：C.I. paratonere (2,3,5,6,7,19,23,48:2、48:3、48:4、57:1、 81:1,122,144,146,150,166,169,177,184,185,202,206,220,221 or 254).

As cyan colorant, for example,：Copper phthalocyanine compound, copper phthalocyanine derivative, anthraquinone compounds or alkali Property dye lake compound.Specifically, it can enumerate：C.I. pigment blue (1,7,15,15:1、15:2、15:3、15:4、60、 62 and 66), phthalocyanine blue, C.I. vat blues or C.I. acid blues.

Binding resin of the content of colorant in toner cores 2 relative to 100 mass parts, more than preferably 1 mass parts And 10 is below mass part, more than more preferably 3 mass parts and 7 is below mass part.

In order to improve the low-temperature fixability of developing toner for electrostatic latent images, and inhibition is stained or streaking (wipes image When image peripheral dirt), toner cores 2 can also be made to contain releasing agent.As the example of releasing agent, can enumerate：Fat (low molecular weight polyethylene, low-molecular-weight polypropylene, polyolefin copolymer, polyolefin-wax, microwax, paraffin take race's hydrocarbon wax Hold in the palm synthetic wax), oxide (block copolymer of oxidized polyethylene wax or oxidized polyethylene wax), the plant of aliphatic hydrocarbon wax Wax (candelila wax, Brazil wax, Japan tallow, jojoba wax or rice bran wax), animal waxes (beeswax, lanolin wax or whale Wax), mineral substance wax (ceresine, ceresin or vaseline), using aliphatic ester as the wax class (montanic acid ester type waxes or castor wax) of principal component Or aliphatic ester is partly or wholly carried out to the wax (deoxidation Brazil wax) after deoxygenated.

In the case where toner cores 2 contain releasing agent, the binding resin of the content of releasing agent relative to 100 mass parts, More than preferably 1 mass parts and 5 is below mass part.

Toner cores 2 can also contain charge control agent as needed.By including charge control agent, it will be able to improve band Electric horizontal or electrification rising characteristic, so as to obtain the toner of durability or excellent in stability.Electrification rising characteristic be The index of electrification level as defined in being charged in short time.Since toner cores 2 have anionic property (negatively charged), institute To use the charge control agent of negatively charged.

Toner cores 2 can contain Magnaglo as needed.It is manufactured using the toner cores 2 containing Magnaglo Toner-particle 1, and in the case that developing toner for electrostatic latent images contains the toner-particle 1, it is used for static latent image developing Toner is used as magnetic single component developer.As preferred Magnaglo, can enumerate：Iron (ferrite or magnet Mine)；Ferromagnetism metal (cobalt or nickel)；Alloy containing iron and/or ferromagnetism metal；Change containing iron and/or ferromagnetism metal Close object；The strong magnetic alloy of ferromagnetismizations processing such as it is heat-treated；Chromium dioxide.

The grain size of Magnaglo be preferably 0.1 μm or more and 1.0 μm hereinafter, more preferably 0.1 μm or more and 0.5 μm with Under.The grain size of Magnaglo within the above range in the case of, easily Magnaglo is made to be evenly dispersed in binding resin.

In the case where developing toner for electrostatic latent images is used as monocomponent toner, the content of Magnaglo relative to The toner total amount of 100 mass parts, more than preferably 35 mass parts and 60 is below mass part, it is more than more preferably 40 mass parts and 60 is below mass part.In addition, in the case where developing toner for electrostatic latent images is used as two-component developing agent, Magnaglo Developing toner for electrostatic latent images total amount of the content relative to 100 mass parts, preferably 20 is below mass part, more preferably 15 matter Measure part or less.

Shell 3 is illustrated below.

Shell 3 contains the thermosetting resin as neccessary composition.Thermosetting resin have sufficient intensity, hardness and sun from Sub- property.In addition, in present specification and claims, thermosetting resin includes for example to have in the monomer of melamine etc Introduce the methylene (- CH from formaldehyde₂) unit.

As thermosetting resin, it can be cited for example that：Melmac, Lauxite (ureaformaldehyde resorcinol class tree Fat), guanamine resin, urethane resin, amide resin, olefin resin or gelatin-gum gum resin.In thermosetting property In resin, preferably melmac or Lauxite, because fixing temperature need not be increased substantially.

Melmac is the condensation polymer of melamine and formaldehyde, and it is three to form the monomer used when melmac Poly cyanamid.Lauxite is the condensation polymer of urea and formaldehyde, and it is urea to form the monomer used when Lauxite.Melamine or Urea can also pass through well-known modification.

Shell 3 can also within the scope of the effect without prejudice to the mode of implementation, as needed comprising thermosetting resin with Outer resin.The content of thermosetting resin in shell 3 is preferably 90 mass % or more and 100 matter relative to 3 total amount of shell % is measured hereinafter, more preferably 95 mass % or more and 100 mass % or less.Thermosetting resin content more than 90 mass % In the case of, shell 3 has sufficient hardness.

Material containing nitrogen-atoms is easy to arrive desired carried charge by positively charged.It is therefore preferable that shell 3 includes to come from three The nitrogen-atoms of poly cyanamid or urea.In order to keep shell 3 fully positively charged, the content of the nitrogen-atoms preferably in shell 3 is 10 matter Measure % or more.

The thickness t of shell 3, such as it can be made to be 7nm or more and 80nm or less.The thickness t of shell 3 is can for example to make The TEM of the section of toner-particle 1 is analyzed with commercially available image analysis software (for example, three paddy business manufacture " WinROOF ") It shoots image and measures.

Hereinafter, being illustrated to inorganic particles 4.

Hereinafter, being illustrated first to the shape of inorganic particles 4.

Inorganic particles 4 are in needle-shaped, and length-width ratio (average major axis diameter/average short axis diameter) is 1.25 or more and 2.5 or less.It is special It is not that the length-width ratio of inorganic particles 4 is preferably 1.3 or more and 2.0 or less.In the case where length-width ratio is 1.25 or more, due to The shape of inorganic particles 4 is kept off spherical, and charge leakage will not reduce, so charge is difficult to put aside used for static latent image developing In toner.As a result, since the carried charge of developing toner for electrostatic latent images will not be excessively increased and (will not excessively charge), It is formed so can image appropriately be carried out.Moreover, because the shape of inorganic particles 4 keep off it is spherical, so local upper stress compared with Greatly.As a result, be easy to destroy shell 3 since there are the part of inorganic particles 4, it is aobvious so as to significantly improve electrostatic latent image The low-temperature fixability of shadow toner.

And be 2.5 below in the length-width ratio of inorganic particles 4, it will not excessively promote charge leakage, so as to The reduction of the carried charge of developing toner for electrostatic latent images is enough set to be inhibited.As a result, the electrostatic on development sleeve is latent As the residual quantity of developing toner will not increase, developing toner for electrostatic latent images can be appropriately recycled, so as to make to show Shadow ghost image is inhibited.

The average major axis diameter and average short axis diameter of inorganic particles 4 meet above-mentioned length-width ratio, and are 300nm or less. Average major axis diameter and average short axis diameter are in the case of 300nm is below, for example, even if can if being under pressure in developer Inorganic particles 4 are inhibited to be detached from from shell 3, so as to steadily maintain charge leakage.As a result, can maintain for a long time Appropriate charging property.Also, since inorganic particles 4 are not detached from from shell 3, so toner cores 2 can be inhibited to expose, so as to Enough inhibition developing toner for electrostatic latent images is attached on development sleeve or the keeping quality of developing toner for electrostatic latent images deteriorates. Moreover, inorganic particles 4 can be inhibited to be protruded from shell 3, to which inorganic particles 4 do not fracture and are included in inside shell 3.In addition, Disengaging in case of inorganic particles 4 fractures, then the stress for being applied to shell 3 becomes smaller, and shell 3 becomes to be not easy to be destroyed, The low-temperature fixability of developing toner for electrostatic latent images is caused to reduce.

In particular, the average major axis diameter of inorganic particles 4 is preferably 50nm or more and 290nm or less.In the flat of inorganic particles 4 In the case that the long diameter of axle is 50nm or more, shell 3 is more easily damaged.And the average major axis diameter of inorganic particles 4 be 290nm with In the case of lower, charge leakage can be steadily maintained, so as to make the low-temperature fixing of developing toner for electrostatic latent images The reduction of property is inhibited.In addition, the average short axis diameter of inorganic particles 4 is preferably 20nm or more and 130nm or less.Inorganic micro- In the case that the average short axis diameter of grain 4 is 20nm or more, shell 3 can be easily destroyed.And in the average minor axis of inorganic particles 4 Diameter is charge leakage can steadily to be maintained, in the case of 130nm is below so as to make developing toner for electrostatic latent images The reduction of low-temperature fixability be inhibited.

Hereinafter, an example of the measurement method of average major axis diameter and average short axis diameter to inorganic particles 4 illustrates. First, from the aggregate of inorganic particles 4,50 inorganic particles 4 are randomly choosed.Also, with scanning electron microscope (for example, Jeol Ltd.'s manufacture " JSM-880 ") to the amplification picture of this 50 50,000 times of shootings of inorganic particles 4.Then, it uses Commercially available image analysis software (for example, three paddy business manufacture " WinROOF "), measures inorganic particles 4 from these amplification pictures The long diameter of axle and short shaft diameter.Then, using their average value as average major axis diameter and average short axis diameter.In addition, by that will put down The long diameter of axle divided by average short axis diameter, can find out the length-width ratio of inorganic particles 4.

Total amount of the amount of inorganic particles 4 in shell 3 relative to toner-particle 1, preferably 0.1 mass % or more And 5.0 mass % hereinafter, more preferably 0.1 mass % or more and 4.5 mass % or less.Inorganic particles 4 in shell 3 contain In the case that the amount of having is 0.1 mass % or more relative to toner-particle 1, shell 3 can be easily destroyed.As a result, can Temperature and load when fixing is set fully to reduce.On the other hand, the amount of the inorganic particles 4 in shell 3 is relative to toning Agent particle 1 be 5.0 mass % it is below in the case of, can make developing toner for electrostatic latent images overcharge and image is formed When the reduction of image color be inhibited.

It is preferred that inorganic particles 4 have than 3 higher hardness of shell.For the difference of hardness of shell 3 and inorganic particles 4, As long as such as according to JIS K5600 (pencil hardness measurement) measure hardness there are differences more than a rank, more preferably For above-mentioned hardness, there are differences more than two ranks.

As inorganic particles 4 type it can be cited for example that：Metal oxide (aluminium oxide, titanium oxide, magnesia, oxidation Zinc, strontium titanates or barium titanate) or silica etc inorganic material particle.

As the preferably acicular titanium oxide microparticle of inorganic particles 4, because its versatility is excellent, the control of shape is easy.With Under, an example of the preparation method of acicular titanium oxide is illustrated.

First, metatitanic acid is obtained by the well-known method such as sulfuric acid process.In this regard, addition sodium hydrate aqueous solution, And heated, then, the metatitanic acid after heating is adequately washed with pure water.Later, hydrochloric acid is added, is further carried out Heating.This is cooled down, be used in combination sodium hydrate aqueous solution carry out neutralize make pH to 7 after, washed and heated.It makes as a result, Standby Titanium Dioxide Rutile Top grade.Then, salinization sodium and ten water tetrasodium pyrophosphates are added, are mixed.Obtained mixture is carried out After firing, burned material is put into pure water, is heated again.Then, it is washed with pure water and removes soluble-salt.By This, prepares acicular titanium oxide microparticle.

In addition, by making firing temperature get higher, the long diameter of axle of acicular titanium oxide microparticle and short shaft diameter can be made to become larger.This Outside, by making firing temperature be lower, the long diameter of axle of acicular titanium oxide and short shaft diameter can be made to become smaller.

In addition, the number for the inorganic particles 4 that the inside of shell 3 includes, can be counted with the bulk density of inorganic particles 4 It calculates.The number for the inorganic particles 4 that the inside of shell 3 includes, for example, relative to 1 toner-particle be 50,000 or more and 550,000 It is a following.

Shell 3 can also contain charge control agent.Shell 3 is due to cationic (positively charged), so can contain There is positively charged charge control agent.

Fig. 3 indicates toner-particle 5 contained in the developing toner for electrostatic latent images involved by other embodiment.Such as Shown in Fig. 3, toner-particle 5 contains toner cores 2, shell 3, inorganic particles 4 and external additive 6.Specifically, in order to carry High fluidity and handlability, the surface of shell 3 are to carry out external addition processing with external additive 6.It is outer for using The external of portion's additive 6 adds processing method, is not specially limited, uses well-known method.Specifically, making outside Under conditions of additive 6 is not embedded in shell 3, using mixing machine (for example, FM mixing machines or nauta mixer (registrar Mark)) carry out external addition processing.

As external additive 6, can enumerate：Silica or metal oxide (aluminium oxide, titanium oxide, magnesia, oxygen Change zinc, strontium titanates or barium titanate) particle.It is preferred that the grain size of external additive 6 is 0.01 μm or more and 1.0 μm or less.

Toner-particle 5 before being handled using external additive 6 (contains toner cores 2, shell 3 and inorganic particles 4 Toner-particle) it is recited as sometimes " toner mother particle ".It is preferred that tune of the dosage of external additive 6 relative to 100 mass parts Toner master batch is 1 mass parts or more and 10 is below mass part, and more than more preferably 2 mass parts and 5 is below mass part.

More than, referring to Fig.1~3, the toning to containing in the developing toner for electrostatic latent images involved by present embodiment Agent particle 1 or toner-particle 5 are illustrated.In addition, the developing toner for electrostatic latent images of present embodiment can also be used Make the so-called monocomponent toner of the Magnaglo further containing ferrite or magnetic iron ore etc.Alternatively, can also with institute Desired carrier mixes and is used as so-called two-component developing agent.

Preferred vector is magnetic carrier.As magnetic carrier, can specifically enumerate：With the load of resin-coated carrier core material Body.As carrier core material, it can be cited for example that：Iron, oxidation processes iron, reduced iron, magnetic iron ore, copper, silicon steel, ferrite, nickel or The alloying pellet of the particle of cobalt etc or these materials and the metal of manganese, zinc or aluminium；Fe-Ni alloy or iron-cobalt alloy etc Particle；Titanium oxide, aluminium oxide, copper oxide, magnesia, lead oxide, zirconium oxide, silicon carbide, magnesium titanate, barium titanate, lithium titanate, titanium The ceramic particle of lead plumbate, lead zirconates or lithium niobate etc；The high-k of ammonium dihydrogen phosphate, potassium dihydrogen phosphate or Rochelle salt The particle of substance.In addition, as carrier core material, the resin that above-mentioned particle (magnetic-particle) is dispersed in resin can also be used Carrier.

The example of resin as coated carrier core material can be enumerated：(methyl) acrylic polymer, styrene polymer Close object, styrene-(methyl) acrylic copolymer, olefin polymer (polyethylene, haloflex or polypropylene), polychlorostyrene Ethylene, polyvinyl acetate, makrolon, celluosic resin, polyester resin, unsaturated polyester resin, polyamide, poly- ammonia Ester resin, epoxy resin, silicone resin, fluororesin (polytetrafluoroethylene (PTFE), polytrifluorochloroethylene or polyvinylidene fluoride), phenolic aldehyde tree Fat, xylene resin, diallyl phthalate resin, polyacetal resin or amino resins.The above resin can individually make With, or two or more use can also be combined.The resin of coated carrier core material, preferably silicone resin.In addition, (methyl) third Olefin(e) acid class means acrylic compounds and methacrylic.

In particular, core material of the ratio of the resin of coated carrier core material relative to 100 mass parts, preferably 1 mass parts with Above and 5 is below mass part.

The grain size for the carrier being measured microscopically with electronics be preferably 20 μm or more and 120 μm hereinafter, more preferably 25 μm with It is upper and 80 μm or less.

In the case where the developing toner for electrostatic latent images of present embodiment is used as two-component developing agent, electrostatic latent image Total amount of the dosage of developing toner relative to two-component developing agent, preferably 5 mass % or more and 20 mass % are hereinafter, more Preferably 5 mass % or more and 12 mass % or less.

The developing toner for electrostatic latent images of present embodiment contains toner-particle, and the toner-particle is with comprising high hard Spend the shell clad surface of thermosetting resin.Nevertheless, can also pass through substantially low fixing temperature and fixing load (fixing Pressure) realize fixing, and appropriately can maintain charging property for a long time.For example, the tune used for static latent image developing of present embodiment It is preferable to use in the image forming method of xerography etc for toner.The developing toner for electrostatic latent images of present embodiment, Due to its characteristic, particularly suitable for having the image forming apparatus of the development section of contact type developing mode.

Contact type developing mode is following developing method：That is, by only making toner (contain from carrying two-component developing agent Have the developer of toner and carrier) magnetic roller on shift, form the thin layer of toner on development sleeve, and make toner It circles in the air from the thin layer of above-mentioned toner to the surface for the photoreceptor for being formed with electrostatic latent image, to make latent electrostatic image developing be toning Agent picture.Using contact type developing mode, if the carried charge of toner rises, remain on development sleeve The amount of toner increases.Therefore, toner can not fully be recycled from development sleeve, easy to produce development ghost image.However, making In the case of developing toner for electrostatic latent images with present embodiment, since the excessive electrification of toner can be inhibited, so Even if the generation of development ghost image can be inhibited if development for a long time using contact type developing mode.

Hereinafter, referring to Fig.1, being illustrated to the manufacturing method of the developing toner for electrostatic latent images of present embodiment.

The manufacturing method of the developing toner for electrostatic latent images of present embodiment includes preparatory process and formation process.Prepare Process is to prepare the process of the toner cores 2 comprising binding resin.Formation process is to be formed as shell 3 to coat toner cores 2 Surface process.In the developing toner for electrostatic latent images as obtained from the manufacturing method of present embodiment, shell 3 contains Thermosetting resin, and include acicular inorganic particles 4 in inside.Acicular inorganic particles 4 are that length-width ratio is 1.25 or more and 2.5 Below, average major axis diameter and average short axis diameter are 300nm inorganic particles below.

When executing preparatory process, as long as making the ingredient other than binding resin (for example, colorant, charge control as needed Preparation, releasing agent and/or Magnaglo) fine dispersion is in binding resin.It, can be with as the method for executing preparatory process Enumerate such as melting mixing method or polymerization.

Melting mixing method carries out in the following way.First, the bonding added by binding resin and as needed Ingredient mixing other than resin, obtains mixture.Also, melting mixing is carried out to gained mixture.Pass through well-known hand Section is by gained melting mixing Wu Fen crushed, to obtain Fen crushed objects.It is classified as well-known method Fen crushed object to obtained by, To obtain the toner cores 2 of desired grain size.

As polymerization, for example,：That is, for example, by disc type nozzle or multi fluid nozzle, make mixed by melting Melting mixing object is atomized in air obtained from similarly being operated in refining method, the method for obtaining toner cores；It is poly- using suspending The legal method to directly generate toner cores；The dispersion copolymerization method of toner cores is directly generated using water-miscible organic solvent, Wherein, in the water-miscible organic solvent, monomer-soluble but resulting polymers are insoluble；The lotion of so-called surfactant- free emulsion polymerization etc Polymerization, direct polymerization in the presence of watersoluble polar polymerization initiator and generate toner cores；Prepare first polarity lotion After aggregated particles, the polar particulate with opposite charges is added and the heterofluocculation method (HETERO-FLOCCULATION) assembled.

Hereinafter, the scheme to formation process illustrates.

One scheme of formation process contains attachment process, supply process and resinification process (the first formation process). Adhere in process, inorganic particles 4 is made to be attached to the surface of toner cores 2.In supplying process, supplied to the surface of toner cores 2 Should the monomer containing thermosetting resin and/or prepolymer shell formation liquid (the first supply process).In resinification process, Resinification (the first resinification process) is carried out to the shell formation monomer of the thermosetting resin contained by liquid and/or prepolymer.

In the case of shell 3 being formed by the formation process containing attachment process, supply process and resinification process, energy Enough developing toner for electrostatic latent images of the manufacture containing toner-particle 1, wherein uniformly divide in the shell 3 of the toner-particle 1 Dissipating has inorganic particles 4.In addition, if executing attachment process to the toner cores 2 after being just made, then toner cores 2 can be improved Preservation in handlability and mobility.

In adhering to process, inorganic particles 4 is made to be attached to the surface of the toner cores 2 as obtained from preparatory process.Make For make inorganic particles 4 be attached to toner cores 2 surface method, it can be cited for example that following methods：Make inorganic particles 4 not Under conditions of being fully embedded in toner cores 2, using mixer (FM mixing machines or nauta mixer (registered trademark)), make tune Toner core 2 and inorganic particles 4 mix.

In the first supply process, shell formation liquid is supplied to the surface of toner cores 2.Shell formation liquid contains heat The monomer and/or prepolymer of thermosetting resin.As the method for supplying shell formation liquid to toner cores 2, it can be cited for example that： The method sprayed to the surface of toner cores 2 with liquid using shell formation, or toner cores 2 are immersed in shell and are formed With the method in liquid.

In order to prepare shell formation liquid, if by such as monomer of solvent, thermosetting resin and/or prepolymer and Other additives (for example, aftermentioned dispersant) added as needed are stirred and are mixed.Type as solvent is not It is particularly limited to, it can be cited for example that：Toluene, acetone, methyl ethyl ketone, tetrahydrofuran or water.

The monomer of above-mentioned thermosetting resin can properly select.In addition, the prepolymer of above-mentioned thermosetting resin is will be hot The degree of polymerization of the monomer of thermosetting resin is increased to the state of the last period rank of a degree of polymer, and also referred to as initial stage polymerize Object or initial condensation object.

In order to improve the dispersibility of the monomer and/or prepolymer of thermosetting resin relative to solvent, shell shape can also be made Contain well-known dispersant at liquid.Shell formation with the content of the dispersant in liquid be, for example, 0.1 mass % or more and 15 mass % or less.If the content of the dispersant in shell formation liquid is 0.1 mass % or more, favorable dispersibility.Separately On the one hand, if the content of the dispersant in shell formation liquid be 15 mass % hereinafter, if can reduce caused by dispersant Carrying capacity of environment.In addition, after the toner-particle 1 or 5 of manufacture present embodiment, can be removed by the processing of washing etc Dispersant.

After the first supply process, in the first resinification process, by arbitrarily polymerizeing or being condensed, shell is formed Resinification is carried out with the monomer of the thermosetting resin contained by liquid and/or prepolymer, to become thermosetting resin.As a result, Shell 3 is formed on the surface of toner cores 2.In addition, resinification also contains not only containing the very high complete resinification of the degree of polymerization The degree of polymerization is moderate part resinification.

It is preferred that the reaction temperature (resinification temperature) of the first resinification process maintains 40 DEG C or more and 90 DEG C of models below In enclosing, 50 DEG C or more and 80 DEG C or less are more preferably maintained.If it is 40 DEG C or more to make reaction temperature, shell can be fully improved The hardness of layer 3.On the other hand, if make reaction temperature be 90 DEG C hereinafter, if can inhibit the excessive high hardness of shell 3.Therefore, energy It is enough easily by fixing when heating and pressurization destroy shell 3.

Another program of formation process contains the second supply process and the second resinification process (the second formation process). In two supply processes, the shell formation liquid of the monomer containing thermosetting resin and/or prepolymer and inorganic particles 4 is supplied. In second resinification process, the monomer of the thermosetting resin contained by shell formation liquid to the surface for being supplied to toner cores 2 And/or prepolymer carries out resinification.In the case of forming shell 3, not making manufacturing process become multiple by the second formation process The miscellaneous developing toner for electrostatic latent images that can manufacture present embodiment.

In the second supply process, the method for preparing shell formation liquid is not specially limited, as long as example, making thermosetting property The monomer and/or prepolymer of resin, inorganic particles 4 and as needed and add various additives (for example, positive charge agent or Dispersant) it is mixed in arbitrary solvent, it suitably stirs and mixes.As solvent, the monomer of thermosetting resin and/or pre-polymerization Object and dispersant etc. use object identical with used substance when preparing shell formation liquid in the first supply process Matter.

In the second supply process, as the method for supplying shell formation liquid to toner cores 2, it can enumerate：It uses The method that shell formation sprays to the surface of toner cores 2 with liquid, or toner cores 2 are immersed in shell formation liquid In method.

In the second resinification process, formed by the monomer and/or prepolymer to thermosetting resin carry out resinification Shell, so as to obtain the developing toner for electrostatic latent images containing toner-particle 1.Tree as the second resinification process Esterified condition and method can use condition same as the resinification condition of the first resinification process and method and method.That is, It is preferred that the reaction temperature (resinification temperature) of the second resinification process maintains in 40 DEG C or more and 90 DEG C or less of range, it is more excellent Choosing maintains 50 DEG C or more and 80 DEG C or less.By making reaction temperature be 40 DEG C or more, the hardness of shell 3 can be fully improved. On the other hand, by making reaction temperature maintain 90 DEG C hereinafter, the hardness of shell 3 can be inhibited to become excessively high, so as to hold Heating and pressurization when changing places through fixing destroy shell 3.

More than, the manufacturing method of present embodiment is illustrated.In addition, in the manufacturing method of present embodiment, Developing toner for electrostatic latent images after formation process, can also as needed and pass through from washing procedure, drying process and The more than one process selected in outside addition process.

In washing procedure, for the developing toner for electrostatic latent images as obtained from executing formation process, such as with Water is washed.

(spray dryer, fluid bed dryer, vacuum freeze dryer subtract in drying process, such as with drying machine Press drying machine), the developing toner for electrostatic latent images after washing is dried.For the electrostatic latent image being easy in inhibiting dry The cohesion for the toner-particle that developing toner is included is, it is preferable to use spray dryer.In the feelings using spray dryer Under condition, for example, being not only dried, while point for being dispersed with external additive 6 (for example, silicon dioxide microparticle) can be also used Dispersion liquid is sprayed.Therefore, it is possible to be carried out at the same time aftermentioned external addition process.

Referring to Fig.1 and Fig. 3, outside addition process is illustrated.In process is added in outside, keep external additive 6 attached It on the surface of toner-particle 1.As the preferred method for making external additive 6 adhere to, following methods can be enumerated：Make External additive 6 is not embedded under conditions of the surface of shell 3, using mixing machine (for example, FM mixing machines or nauta mixer (registered trademark)), so that the developing toner for electrostatic latent images containing toner-particle 1 and external additive 6 is mixed, to manufacture Developing toner for electrostatic latent images containing toner-particle 5.

It is illustrated to the developing toner for electrostatic latent images of present embodiment is fixed to the method in recording medium.This The fixation method of embodiment includes that toner supply process and load assign process.In toner supply process, by electrostatic The surface of image development toner supply to recording medium.In load assigns process, to electrostatic has been supplied on surface The recording medium of image development toner assigns 5N/cm²Above and 10N/cm²Load below.

It is as follows before developing toner for electrostatic latent images is supplied to recording medium surface in toner supply process It is described that toner image is made to develop.When toner image being made to develop, for example, in image forming apparatus, pass through corona discharge etc Means make image carrier surface charge.Later, the surface of the image carrier of electrification is exposed with light beam etc., makes the table Face is in electroneutral, and electrostatic latent image is formed on image carrier surface.Then, the table to the image carrier for being formed with electrostatic latent image Face assigns developing toner for electrostatic latent images.The exposure portion being exposed attracts developing toner for electrostatic latent images, makes electrostatic latent image Development is toner image.Then, toner image is transferred to recording medium from image carrier by using transfer roll, thus will Developing toner for electrostatic latent images is supplied to recording medium.

In load assigns process, the recording medium to developing toner for electrostatic latent images has been supplied on surface assigns 5N/cm²Above and 10N/cm²Load below.Developing toner for electrostatic latent images is fixed in recording medium as a result,.

Referring to Fig.1 and Fig. 4 assigns process to load and is described in detail.Fig. 4 indicates to assign process for executing load One example of fuser 7.Fuser 7 has heating roller 9, pressure roller 10, heat source 11, temperature detection part 12 and separating component 13.Heating roller 9 has heat source 11 (for example, halogen heater), and is heated to recording medium 8 by the heat source 11.Temperature Detection part 12 controls the heating temperature of heating roller 9.Pressure roller 10 is oppositely disposed with heating roller 9, and to recording medium 8 Assign load.Separating component 13 makes the recording medium 8 for assigning process through overload be detached from heating roller 9.

Specifically, make to be supplied with the recording medium 8 of developing toner for electrostatic latent images from heating roller 9 and pressure roller 10 it Between pass through, assign heat and load to recording medium 8 and developing toner for electrostatic latent images.Then, aobvious included in electrostatic latent image The shell 3 of toner-particle in shadow toner is destroyed, and toner cores 2 melt or soften and be fixed in recording medium 8. In addition, load when fixing can be adjusted by suitably changing roller load and gripping width.Gripping width refers to pressure roller 10 With the contact width between heating roller 9.Later, recording medium 8 is peeled off from heating roller 9 using separating component 13 and is detached.

In the fixation method of present embodiment, for example, used by realized so-called of heating roller and pressure roller plus Hot pressure fixing method.The inorganic particles 4 that shell 3 is included become the starting point destroyed, and shell 3 is easy quilt due to heating and pressurizeing It destroys.As a result, fixing temperature when developing toner for electrostatic latent images is fixed in recording medium can be reduced fully And fixing load.

It, can be by fixing load drop according to the fixation method for the developing toner for electrostatic latent images for having used present embodiment As low as 5N/cm²Above and 10N/cm²Range below.If being fixed load in 10N/cm²Hereinafter, will not then make note when fixing The pressure overload of recording medium.Therefore, the durability of recording medium and transporting are excellent, and can inhibit to draw because of overvoltage The generation of the defect (for example, gauffer) of the recording medium risen.Further, it is possible to inhibit component (the especially rubber of composition fuser Component) deterioration and cost increase.On the other hand, if fixing load is in 5N/cm²More than, then low-temperature fixability is good.This Outside, the fixing load of general developing toner for electrostatic latent images is 20N/cm²Above and 100N/cm²Below.

Fixation method according to the present embodiment, with the latent electrostatic image developing for using shell inside not include inorganic particles 4 It is compared comprising the developing toner for electrostatic latent images for connecing torulose inorganic particles with toner or using inside shell, energy It is enough fully to reduce its fixing temperature.As a result, since load caused by due to heat is reduced, so record can be improved The durability of medium.Further, it is possible to which the deterioration of the component of composition fuser and cost is inhibited to increase.

In addition, in the fixation method of present embodiment, it is, for example, 20msec or more and 70msec that can make fixing time Hereinafter, preferably 20msec or more and 50msec or less.

[embodiment]

Hereinafter, carrying out more specific description to the present invention by embodiment.In addition, the present invention is not limited by following embodiment It is fixed.

(preparation of acicular titanium oxide microparticle)

Titanium oxide microparticle A

First, metatitanic acid is obtained by sulfuric acid process.To the metatitanic acid, sodium hydrate aqueous solution (a concentration of 50 matter is added Measure %), it is 4 times of molar equivalents to be added to sodium hydroxide relative to titanium oxide, and is heated 2 hours with 95 DEG C.With pure water to gained Object is fully washed.Later, addition hydrochloric acid (a concentration of 31 mass %), is added to the ratio (chlorination of hydrogen chloride and titanium oxide Hydrogen oxygen titanium) it is 0.26, and keep the temperature of hydrochloric acid boiling and heat 1 hour.It is cooled down later, with 1N- sodium hydroxide water Solution is neutralized, and makes pH to 7.It is washed and is dried later, Titanium Dioxide Rutile Top grade is made.Relative to 100 mass parts Gained Titanium Dioxide Rutile Top grade adds the sodium chloride of 100 mass parts and ten water tetrasodium pyrophosphates of 25 mass parts.Use vibratory milling Machine to gains mix within 1 hour, obtains mixture.Then, gained mixture is burnt into 1 hour with 850 DEG C with electric furnace, is obtained To burned material.Gained burned material is put into pure water, is heated 6 hours with 80 DEG C.Later, solubility is removed with pure water Salt prepares titanium oxide microparticle A.The shape of titanium oxide microparticle A be length-width ratio be 1.75, average major axis diameter is 140nm, average minor axis Diameter is 80nm.

Titanium oxide microparticle B~I

Prepare titanium oxide microparticle B~I of shape shown in table 1.

[table 1]

Embodiment 1

(preparatory process)

Using FM mixing machines, with the polyester resin of 100 mass parts, (Kao Corp manufactures, acid value 16mgKOH/g, hydroxyl Value 22mgKOH/g, Tm100 DEG C of softening point, 48 DEG C of glass transition temperature Tg), colorant (the C.I. pigment blue 15s of 5 mass parts: 3 types, copper phthalocyanine) and the ratio of releasing agent (ester type waxes, Japan Oil Co manufacture " WEP-3 ") of 5 mass parts mixed, Obtain mixture.Using the extrusion shaping machine " PCM-30 " of manufacture (Co., Ltd. pond shellfish) of twin-screw, to gained mixture into Row melting mixing, obtains mixture.It uses mechanical crusher (" TurboMill " of the manufacture of FREUNDTURBO Co., Ltd.) Gained mixture is crushed, is classified, is obtained followed by grader (" Elbowjet " of Nittetsu Mining Co., Ltd.'s manufacture) The toner cores for being 6 μm to Volume Median diameter.

(attachment process)

To toner cores, titanium oxide microparticle A is added, until its adhesion amount is up to 1 mass % relative to toner cores total amount. It is mixed with FM mixing machines, to make titanium oxide microparticle A be attached to the surface of toner cores.

(supply process)

The three-necked flask that volume is 1L is positioned in 30 DEG C of water bath.In flask, with hydrochloric acid by ion exchange water The pH of (300mL) is adjusted to 4.By initial stage aqueous solutions of polymers (Showa Denko K. K's system of the melamine methylol of 2mL Make " mirben resinSM-607 ", 80 mass % of solid content concentration) it is dissolved in the ion exchange water, obtain shell shape At with liquid.The toner cores by attachment process of 300g are added with liquid to shell formation.

(resinification process)

Shell formation liquid and toner cores are stirred 1 hour with the speed of 200rpm.The ion exchange of additional 500mL Water is stirred the content of flask with 100rpm, is made the temperature rise of flask interior with 1 DEG C/min of heating rate on one side on one side To 70 DEG C.After heating, the content 2 hours that continues to stir flask with 70 DEG C and 100rpm.Then, sodium hydroxide is added, will burn The pH of the content of bottle is adjusted to 7.Then, flask content is made to be cooled to room temperature, to obtain containing used for static latent image developing The liquid of toner.

(washing procedure)

Then the toner is collected by filtration from the liquid containing developing toner for electrostatic latent images using Bu Hena funnels Wet filter mud cake.So that the wet filter mud cake of toner is dispersed again in ion exchange water, washs toner.Above-mentioned is collected by filtration And dispersion is repeated 5 times.

(drying process)

So that the developing toner for electrostatic latent images of 2g recycled is scattered in the water of 20g, obtains dispersion liquid.In the dispersion At the time of the conductivity of liquid becomes 10 μ S/cm or less, toner is recycled, and placed 48 hours in 40 DEG C of environment, so that it is dry It is dry.

(outside addition process)

Dry type silica (grain size is carried out to the surface comprising the toner-particle in toner after the drying：0.1μ M) external addition processing, it is 0.5 matter relative to toner total amount to add processing to the external additive amount of dry type silica % is measured, to obtain the developing toner for electrostatic latent images of embodiment 1.The developing toner for electrostatic latent images is carried out aftermentioned Evaluation.The evaluation result is shown in Table 2 below.In addition, by the SEM picture (magnifying powers of the developing toner for electrostatic latent images： 30000 times) it indicates in Figure 5.It can obviously be learnt by Fig. 5, the dry type silica equably external electrostatic for being added to embodiment 1 The surface of image development toner.By the SEM picture (magnifying powers of fixing treated developing toner for electrostatic latent images： 3000 times) it indicates in figure 6.It can obviously be learnt by Fig. 6, in the developing toner for electrostatic latent images of embodiment 1, after fixing, Shell is destroyed by titanium oxide microparticle, the destruction position outflow in elongate shape of the toner cores of melting from shell.

Embodiment 2

Other than replacing titanium oxide microparticle A with titanium oxide microparticle B, operation same as Example 1 is carried out, reality is obtained Apply the developing toner for electrostatic latent images of example 2.

Embodiment 3

Other than replacing titanium oxide microparticle A with titanium oxide microparticle C, operation same as Example 1 is carried out, reality is obtained Apply the developing toner for electrostatic latent images of example 3.

Embodiment 4

Other than replacing titanium oxide microparticle A in addition to using titanium oxide microparticle D, operation same as Example 1 is carried out, is obtained The developing toner for electrostatic latent images of embodiment 4.

Embodiment 5

Other than replacing titanium oxide microparticle A in addition to using titanium oxide microparticle E, operation same as Example 1 is carried out, is obtained The developing toner for electrostatic latent images of embodiment 5.

Embodiment 6

Other than replacing titanium oxide microparticle A in addition to using titanium oxide microparticle F, operation same as Example 1 is carried out, is obtained The developing toner for electrostatic latent images of embodiment 6.

Comparative example 1

Other than replacing titanium oxide microparticle A in addition to using titanium oxide microparticle G, operation same as Example 1 is carried out, is obtained The developing toner for electrostatic latent images of comparative example 1.

Comparative example 2

Other than replacing titanium oxide microparticle A in addition to using titanium oxide microparticle H, operation same as Example 1 is carried out, is obtained The developing toner for electrostatic latent images of comparative example 2.

Comparative example 3

Other than replacing titanium oxide microparticle A in addition to using titanium oxide microparticle I, operation same as Example 1 is carried out, is obtained The developing toner for electrostatic latent images of comparative example 3.

Comparative example 4

Other than not containing titanium oxide microparticle, operation same as Example 1 is carried out, the electrostatic for obtaining comparative example 4 is latent As developing toner.

By the evaluation result table of the developing toner for electrostatic latent images as obtained from embodiment 2~6 and comparative example 1~4 Show in table 2.

The evaluation method of the developing toner for electrostatic latent images obtained in following presentation Examples and Comparative Examples or measurement side Method.

(1) development ghost image evaluation

Using ball mill by the load of the toner as obtained from Examples and Comparative Examples and 90 mass parts of 10 mass parts Body (FS-C5300DN carriers) mixes 30 minutes, makes two-component developing agent.Also, determined using having repacked into adjust The printer (Kyocera Document Solutions Inc. manufactures " FS-C5250DN ") of shadow temperature is used as evaluating apparatus.By institute as above State the toner Cartridge that the two-component developing agent obtained like that puts into the developing apparatus of evaluating apparatus.In the electricity for connecting evaluating apparatus Source and after enabling evaluating apparatus operating stably, export image, and as initial pictures.Then, in ambient temperature and moisture environment Under (temperature is 20 DEG C or more and 23 DEG C hereinafter, relative humidity is 50%RH or more and 65%RH or less), with 4% or more and 5% Printing coverage rate below after continuous printing 100,000, obtains solid image.

For initial pictures and solid image (image after printing 100,000), with Macbeth reflection of the concentration (SAKATA INX ENG.CO., LTD manufacture " SPM-50 "), to image color (ID), brightness (L^*), form and aspect (a^*) and form and aspect (b^*) surveyed Amount.Then, Δ E is found out by following formula, and is evaluated according to following benchmark.

Δ E={ (a^*)2+(b^*)2+(L^*)2}×1/2

◎ (very good)：Δ E is 3 or less.

Zero (good)：Δ E is more than 3 and is less than 5.

× (poor)：Δ E is 5 or more.

(2) evaluation of image deterioration

Identical with the above-mentioned evaluation of (1) operation is carried out, is obtained solid after initial pictures and continuous printing 100,000 Image.For the initial pictures and solid image, with (SAKATA INX ENG.CO., the LTD manufactures of Macbeth reflection of the concentration " SPM-50 "), image color (ID) and grey haze value (FD) are measured.Then, initial pictures obtained by visual confirmation and solid Image.It is evaluated according to following benchmark.

◎ (very good)：ID is that 1.30 or more, FD is less than 0.005, and no generation is uneven in image.

Zero (good)：It less than 1.30, FD is 0.005 less than 0.015 that ID, which is 1.10, and is not had in image It is uneven.

× (poor)：It is 0.015 or more that ID, which is less than 1.10, FD, and is produced in image uneven.

(3) fixing temperature (low-temperature fixability)

It is aobvious to the electrostatic latent image obtained in Examples and Comparative Examples using heating compression type fuser as shown in Figure 4 Shadow carries out fixing processing with toner, and measures fixing temperature.Specifically, with 5 DEG C of scales every time, by fixing temperature from 100 DEG C change to 200 DEG C, by 1.0mg/cm²Developing toner for electrostatic latent images be fixed on 90g/m²Paper after, visual confirmation is fixed Shadow situation, and the minimum temperature of state is well fixed as fixing temperature using making toner reach.In addition, the survey of minimum temperature Amount condition be speed be 230mm/sec, gripping width 8mm, clamping by the time are 35msec.It is carried out according to following benchmark Evaluation.

◎ (very good)：Fixing temperature is 150 DEG C or less.

Zero (good)：Fixing temperature is 155 DEG C.

× (poor)：Fixing temperature is 160 DEG C or more.

The structure of the fuser is as described below.The plug (φ 26mm) of heating roller is the aluminium that length is 1mm, and thickness is 300 μ The silastic-layer of m is coated on the plug.Also, the paraformaldehyde tree that silastic-layer is 30 μm used as the thickness of release layer Fat pipe coats.Heating roller is internally provided with halogen heater, is heated to heating roller by the radiant heat of the heater.And And by the temperature detection part set on heating roller, the temperature of heating roller is detected, and heater is controlled according to the testing result The input of power supply.In pressure roller, plug (φ 12mm) is coated with thickness for the silicon rubber of 8mm, also, silicon rubber is with poly first Urea formaldehyde pipe coats.

[table 2]

The developing toner for electrostatic latent images of present embodiment includes inorganic particles inside shell.Can be apparent by table 2 Know, the developing toner for electrostatic latent images of present embodiment, since appropriate charging property can be maintained for a long time, so even if print After brushing 100,000, it can also inhibit image ghost image or image deterioration, to realize good picture quality.Also, due to nothing Machine particle becomes the starting point that shell destroys, so significantly improving low-temperature fixability.

The developing toner for electrostatic latent images of comparative example 1 is more than 2.5 inorganic particles comprising length-width ratio inside shell.Cause This, carried charge significantly reduces, and excessively promotes charge leakage.As a result, in the case of continuous printing 100,000, due to Toner amount on development sleeve increases, so the toner remained on development sleeve can not be recycled fully, causes to develop The generation of ghost image.Moreover, because charging property excessively reduces, so there is image deterioration.

The developing toner for electrostatic latent images of comparative example 2 is less than 1.25 inorganic particles inside shell comprising length-width ratio. It is therefore contemplated that：The shape of inorganic particles leads to the reduction of charge leakage close to spherical, to which many charges savings exists In toner.As a result, since the carried charge of toner rises and excessively charges, so after continuous printing 100,000, toning Agent becomes strong to the electrostatic adhesive force of development sleeve, can not fully recycle toner, leads to the generation of development ghost image.In addition, nothing Machine particle is close to spherical shape, and therefore, the local stress for being applied to the inorganic particles dies down, and rising for destruction cannot be arranged in shell Point, to which low-temperature fixability is not improved.

The developing toner for electrostatic latent images of comparative example 3 is more than the inorganic of 300nm comprising average major axis diameter inside shell Particle.Therefore, inorganic particles are detached from from the surface of toner-particle, and the ingredient that wax etc. constitutes toner cores is exposed to surface.Its As a result, after continuous printing 100,000, the adhesive force on toner to developer roll becomes strong, generates the attachment or aobvious to development sleeve Shadow ghost image.Moreover, because generating the disengaging of inorganic particles or fractureing, the starting point for destroying shell is reduced, so low-temperature fixability does not have It is improved.

The developing toner for electrostatic latent images of comparative example 4 is inside shell not comprising inorganic particles.Therefore, can recognize For：Charge leakage is not embodied, to put aside many charges in toner.As a result, due in charged toner amount It rises and excessively charges, so after continuous printing 100,000, toner becomes strong to the electrostatic adhesive force of development sleeve, can not be abundant Toner is recycled, the generation of development ghost image is caused.Moreover, because there is no the starting points for destroying shell, so low-temperature fixability does not have It is improved.

Claims (1)

1. a kind of manufacturing method of developing toner for electrostatic latent images, including：

Preparatory process prepares the toner cores containing binding resin；With

Shell is formed as coating the surface of above-mentioned toner cores by formation process,

Above-mentioned formation process includes：

Adhere to process, inorganic particles is made to be attached to the surface of above-mentioned toner cores；

Process is supplied, is supplied to the above-mentioned surface for the above-mentioned toner cores for being attached with above-mentioned inorganic particles containing thermosetting resin The shell formation liquid of monomer and/or prepolymer；With

Resinification process carries out above-mentioned shell formation with the monomer of the above-mentioned thermosetting resin contained by liquid and/or prepolymer Resinification,

Above-mentioned shell contains above-mentioned thermosetting resin,

The length-width ratio of above-mentioned inorganic particles be 1.25 or more and 2.5 hereinafter, average major axis diameter and average short axis diameter be 300nm with Under, above-mentioned inorganic particles are attached directly to the surface of above-mentioned toner cores and the inside included in above-mentioned shell,

Above-mentioned binding resin is polyester resin,

The monomer and/or prepolymer of above-mentioned thermosetting resin are the pre-polymerizations of melamine methylol and/or melamine methylol Object,

Above-mentioned shell formation does not contain dispersant with liquid.